1. Field of the Invention
The present invention relates to a label tracking system, and more particularly, to a linerless label with a radio frequency transponder embedded therein for identification and tracking purposes.
2. Description of Related Art
In the automatic identification industry, the use of radio frequency (RF) transponders (also known as RF/ID tags) has grown in prominence as a way to track data regarding an object to which the RF/ID tag is affixed. An RF/ID tag generally includes a semiconductor memory in which digital information may be stored, such as an electrically erasable, programmable read-only memory (EEPROMs) or similar electronic device. Under a technique referred to as "backscatter modulation," the RF/ID tags transmit stored data by reflecting varying amounts of an electromagnetic field provided by an RF/ID interrogator by modifying their antenna matching impedances. The RF/ID tags can therefore operate independent of the frequency of the energizing field, and as a result, the interrogator may operate at multiple frequencies so as to avoid radio frequency (RF) interference, such as utilizing frequency hopping spread spectrum modulation techniques. Passive RF/ID tags extract their power from the electromagnetic field provided by the interrogator, while active RF/ID tags include a radio tranceiver and a battery power source which enable them to transmit a signal to a remote reader. While active RF/ID tags have greater range and capacity than passive RF/ID tags, they are also physically larger, more expensive and have a life limited to the capacity of the battery.
Since passive RF/ID tags do not include a radio transceiver, they can be manufactured in very small, light weight and inexpensive units. Passive RF/ID tags are particularly cost effective since they lack a power source. In view of these advantages, passive RF/ID tags can be used in many types of applications in which it is desirable to track information regarding a moving or inaccessible object. One such application is to affix passive RF/ID tags to wrist bands or other items to identify people for security purposes. Another application for passive RF/ID tags is to attach them to express parcel delivery packages and airline baggage so that information regarding their origination and location could be easily identified.
A problem exists in finding an efficient and cost-effective way of attaching the passive RF/ID tags to the items to be inventoried or tracked. Because of their small size, these RF/ID tags have been affixed to standard liner labels and other similar adhesives employing peel-away liners, utilizing the RF/ID tag's tracking properties in a convenient attachable package. Some problems exist, however, with the linered RF/ID systems. Due to the fact that liners must be peeled away before use, environmental and safety issues are raised. After peeling away from the label, the liners must be disposed of, creating extra waste as well as an associated cost of handling. Also, when using portable printers and applying the labels to the selected item after printing, spent liners that are discarded on the ground can cause potential slip and fall situations. Further, the rolls of media with liners for a given diameter produce lIess labels than rolls without liners, translating to more downtime for operators to change the rolls. Accordingly, it would be desirable to produce a linerless label tracking system that would incorporate the informational capabilities of a passive RF/ID tag into the convenience and cost-effectiveness of a linerless label.